The unidentified male was out with family on a pontoon rental when they all decided to swim close to the shore around 7 p.m. in Lake Marburg at Codorus State Park, York County Coroner Pamela Gay said.
The victim was reportedly a good swimmer and was using a camera under water. His family realized he hadn't resurfaced, and so all went back in the waters to find him, Gay said.
Two Good Samaritans who they flagged down for help also aided in the search.
The man's body was eventually found and attempts to rescusitate him were unsuccessful, Gay said. He was pronounced dead at UPMC Hanover Hospital at 7:13 p.m.
The man's identity was not immediately being released.
Click here to follow Daily Voice Bristol and receive free news updates.